Process of incubation of eggs



Z. Y. KUO

PROCESS OF INCUBATION OF EGGS Filed Aug. 12, 1959 d eito twisting or upturihgfoffblood vesselforfl Patented Aug. 31, 19 4 ,ajszaw I Es rATENr o FFICE" Zing; YangKuo,BostonMass h a Application August 12, 1939, sea-n No. 2 89,9l2

f T in maths; (cit us-#44 The present invention ,tela sa the incu atio of 1 eggs and more particularly to, .a; method whereby the eggs may bev so: turnedlot manipulatedthatl a substantiallyliigher percentage of hatching 'may' be obtained astcomparedwiththe ba rat'usfm V 7 It is an establishedf'act that the embryo; as it normally reposes atthetop of the eggfwillybe positioned with the headto theleftljviwing'the egg Irom' thelarge, end, withQits"longitudinal axis horizontal; Withthis fact ihmindgrhave develeped the followingldescribed process and'ap! paratus which turns'and manipulatesthe eggs in a manner especially advantageous for embryos thus'positionedf l In theflfertile egg, thel embryo' liesuponthe yolk body; which] it gradually absorbs during rowth.

The embryo normally tends to'rise to the, top: of the egg, particularlyjdurin theflrstfhalfioffthe incubation period, andiitis welllise'ttl'ed thatsuch movementisvery desirable, resulting in a :much

higher percentage of hatching than wherethe eggs remainquiescent." It is the eomrnon'prac tics in incubators, as at present constructed; to

provide, for theturning. orftilting of the. e'ggsati more or less frequent intervals in order to cause such, displacement of the? embryo andjto produce. this advantageous return movement.

Heretoforefsuch ;movement' of "the egg been effected by tiltin the egg trays alternately first in one direction and thenln the other, to

tumor tilt ,thefegg si so that theembryo will be displaced em its originalt'position at the top of thejegg to a point beneathgor carried alternately first toone side and then to; theothenthe longitudinal axis of theegg at-f such times, being er; dinarily horizontallydisposed. I, Ijhave discovered that ,by this method :"of" tilttheloriginal position" ofthe ernb'ryo will be yolksaef n v n I have also toundfthat byin'cluding the longitudinal axis, of, the egg [at an "angle to the hori zonta'lf the large -end elevated, androtating the e ggs about such inclined longitudinal axis and controlling the direction-and'extentand time interval of suoh' rotation of the "egg,- particularly I during the early'stageg-ofincubation, this possibilityiotinjury to and de'ath of the embryowlll be} greatly reduced sothat avery substantially 'hlgh'er pei centage of hatchingswill be obtained then *heretoiore' attainable methods-and apparatusd I wlthfthe a e The present' Ilnvention, therefore} consists in results secured from presentf rnethods and an? the method orsu porni g' and rotating or turning,

and manipulating the veggs hereafter described" in connection with the accompanying drawing.

In accordance with th present invention, the egg is supported withjit longitudinal axis inclined to the horizontal and it'slar'geend elevated and during theffirst stage, comprising-the first sevengdays of incubation, is, periodically rotate'd about its inclined longitudinal axis, but always in a clockwise direction and to an extent varying from approximately thirty to sixty, degrees, the

time intervalsbetvveen turning varying with the extent ofwthe turning, being shorter forthe smaller amplitudes of movement, and longer for the larger amplitudes;

Forlexarngle; lithe egg is, to be rotated each time. through""thirtf'degrees; these turnings should occur every two hours? if; on'th'e other,

hand, thearnplitude of turning isforty degrees,

this should' b'e done every threehours. Forsixty' degrees, ther'elshouljd be a four hour intervall' 'The tirnefrequired for the turning movementis always in a clockwise direction and through amounts not varying substantially from a thirty degree minimum to sixty degree" maximum, with intervals approximately thoseabove mentioned, a substantial" reduction in mortality will result, ranging from five to ten per cent. i

The advantages: i'ncliningthe egg witlrits large end elevated is that it tends to prevent the embryo from falling to the middle or small end of; the eg which may'interfere with the hatchingin thelater stages. In the inclined position the orientation of thehead of the"'enibryo is easier to control by pronerturning than'with horizontal positioning; Also the inclinedposi during the first seven-daystage reduces the more tion= keeps thewhit'eaway fromtherlarge end where it mightin some later stage interfere with the movements'of the embryo in changing its position. A

One of the reasons why I believe that the above specified direction, extent and periods of turning talityi of theteinbryo is that with the clockwise rotation and with the headpositioned to the left,

which is the usual position in the large majority of eggs, the embryo will float to the top of the yolk with its head upward, whereas if the rotation were counterclockwise, this return movement of the embryo would have to be with the tail upward, which is more difficult, especially from the fifth to the seventh days when the head'has grown heavy. Furthermore, there is less liability of the embryo changing its original advantageous position, at least in th large majority of eggs Where the head is to the left. I

As to the extent of rotation, any turning in excess of substantially sixty degrees requires an excessive returnmovement of the embryo and may result in a shifting of its original orientation.

The time intervals selected are with a view to giving the embryo a sufiicient time to return to the top of the yolk, and while these intervals may be substantially longer than required during the first days of this first stage, a three-day embryo; for example, ordinarily floating back to the top of the yolkwithin a few minutes after the turning, this extended period affords ample time for such return during the last day of the stage, when the'return movement is very much slower.

The traveling of the embryo from other parts of the egg to the top of the yolk is effected in The third alternative is first to turn the egg 90 in a counterclockwise direction, and then to return it to its original position in three steps of 30 each in a clockwise direction.

, The reason for turning the egg more in the counterclockwise direction than in the clockwise direction during this second week is to prevent the head of the embryo from shifting to the small end of the egg and also prevent the head in these alternative procedures is not so important during the second as in the first week, because there is very little possibility of the embryo returning to its original place within a few hours after the egg has been turned. It is imthe early days by the movement or floatingof V the entire yolk sac, the embryo remainingpassive, but as the embryo absorbs its nutrition from the yolk and becomes larger and heavier and the yolk smaller, the amnion enclosing the embryo contracts and such contraction during the later days of this first stage, such as the sixth and seventh days, is chiefly responsible for sending the embryo back to the top of, the egg after the turning. If, however, such turning had placed the embryo in an unfavorable position as, for

example, by counterclockwise rotation or an ex-' cessive extent of rotation as by the present meth- 0d. of tilting, this contraction of the amnion may be insufiicient to return the embryo to the top of the yolk, or at least may retard it greatly. The most favorable conditions for the return or the embryo to the top of the yolk are, as above set forth, where the rotation is clockwise and the extent is from approximately thirty to sixty degrees, and the interval from ,two to four hours, and it is by maintaining these optimum conditions that the minimum mortality in the embryo I at this stage is obtained.

During the secondstage of my improved method of incubation, several alternative series of steps may be adopted. A first alternative for the second seven-day stage is to permit the egg to/remain quiescent with no turning whatsoever for the eighth and ninth days. During this twoday period, the contractions of the amnion are most violent and additional movement of the embryo from turning'or rotation of the egg is not necessary. H v

Beginning with, thetenth day, the egg maybe turned alternately clockwise and counterclock wise during the remainder of the second week. The purpose or these turnings 0r rotations is to keep the yolk from adhering and bec-omingfixed, particularly during the tenth and eleventh days whenthe contractions of the amnion diminish greatly. Also to assist or facilitate movement of the much reduced yolk sac in rising and folding over the abdomen of the embryo. h

A second alternative for this period, is to turn the egg first 90 in a counterclockwise direction,

other 45 in theclockwise direction.

portant, however, that the timing or interval kfollowin'g the counterclockwise turnings be longer than those following the clockwise turning.

, It is also important that the clockwise turning doestnot exceed for if a greater movement than this is employed, the header the embryo may shift to the small end of the eg or fall on its side or onto the abdomen. Turning more than counterclockwise is to be avoided, for such anextent of turning may bring the embryo to the bottom of the egg and may shift the body to a wrong position.

Any of the above alternative series of steps for thesecondweekwill give substantiall the same satisfactory'results. If desired, any of these series may be continued until the eighteenth day when, as with the present method, the eggs will be transferred to the hatching trays.

In view of the fact that the mortalitycf the embryo during this first week is so substantially reduced where the turnings areall clockwise and of restricted amount, I believe that there is some distinct advantage to the embryo in maintaining the head above the tail when the embryo is returning to the top after the egg has been turned.

It is my opinion that this reduction in mortality is secured chiefly in those eggs in which the embryo is positioned with its head to the left, which is the normal and usual position, as above explained. 'As to those eggs in a hatch- 7 ing where the embryo is turned to the right, I

- ter results than the ordinary method of support ing the eggs with their longitudinal axes horizontal and alternate tilting or turning'them in excessive amounts. But be that as it may, the total net result gained by my method is a very substantial reduction in mortality.

Whilethe foregoing described manipulation or turning of the eggs in the process of incubation may be carried out by hand, it obviously may be performed much more expeditiously and economically if accomplished by mechanism which will handle large numbers of eggs at a time and automatically efi'ect the turning at the desired intervals. Accordingly, I have devised an apparatusoperating in accordance with my improved process and have illustrated the same in the accompanying drawings in which Fig. 1 is a side elevation of the complete apparatus'; Figs. 2 and 3 are enlarged details in top plan and vertical sections respectively showinga circular egg tray and method of attachment to the tubular actuating shaft; Fig. 4 is a diagrammatic detail illustrating the automatic control of. the motor for rotating such shaft shows-11a controlling? suitable .for: usekfduring the: second; of: thei incubation. perlodr.

' IAs' illustrated in:ItheIfdravving; my; improved apparatuszi comprises: an inclined; shaft; adapted tor-support transversely." thereon. a; series off (211? cularl egg traysanm arranged'itoz be rotatediaat stated intervals) through the: desired; portion of a reyolutionzbyi an intermittently operating elec; tric; motor; This -a utcmatically controlledIto start and. stop and-tortum inI-theIIde;-

sired direction at predetermined; times anditqpredetermined; degrees I-by interchangeable Icontr0l disks forxcloslngand'opening andIreverslng suit! I .ableswltch mechanismsforrtheimotorr I Theishait I with the ;:egg trays :mountedi' thereon. is positioned 1 within a cylindrical: casing; and meanszare; proassess? I 'equipped wlthia control aiskidesgmarmr use amngims first Iweemr; incubation;- chan s ingn'earthe'inlddle thereof; t "r I Access: to: the interior of. the casings for the purpose of inserting and removing the egg trays isxafiorded by means ofIthe-two pairs of hinged I doors 69 with suitable clasps or other-fastener vlded for supplying and 'regulatingqheatfor in- I cubation as: well as: the proper humidity, alliun der the control of I the usual IthemrometersItherI- mostataetc; I r

Referring to Figslzly2;andf tisofthe drawing;

aIhollow actuating ShafifI -I is mounted at; an

angle of approximatelyfifl .with-Ithe vertlcalin fixed bearings at the upper-and the; lower ends of the;shaft. Upon this shaftl lshlGgIXlOllDtBd lar; shaft; I I- isprovided withlarserles of. spaced openings or" slots I I1 adapted; to receive the hooks Ill or bentoverImembers I9 WhiChrBrIEfiISU passed .3;

through the openingsI or slots; audI-Ithemmoved downwardly into locking; position-;1I asII shown: in

Fig.3. 1 I v Preferablml the circular eggg IItrays areIIprm-I and to retain the eggs in the desiredtposltlon' I whlch'lswith the large enduppermostl This shaft I I I,; carrying: its series: of: :cgg, trays; II3, -ls rotated by means of theI motor-fiathrough pinion 21 and worm 29 wherebythe relatively slow turningmovementflissecured: I II The rotating shaft, I with n its Ijsllplllortecr;egg trays; is: enclosed within a fixed-Icirculari casing,

31 with closed' ends. and. sides, except-ffor'I a pore tion of; the sidewalladjacentIt-he bottomendsofs the casing where such sldewallI'is ornltted; ln-

dicated generally at 33; I 'lhissfcasingpwhichi.

I is stationary, is supported: on a suitableIIframeI- work 35 which; alsoIIcomprisesII the support: on standard for the upperI bearingsofjthe, rotate I ing shaft. I I I I l I Opposite the openportionof-the-wa1hcf the casing is located the -I electrical heating; element 30 I having a suitable I-switch'; I; on; the; outdde: of the base. I

Ij Adjacent the heating; unit is, amenities,

fan driven by the motor laundrcontrolled;

from thesw-itch 41. t V I Humidified air is supplied from. suitableIhuI- midlfying apparatus llin the; base-of the-ap paratus through supply return :ducts I51: and? 53. respectively with inlet and exhaust; openings 55 and 51 opposltethe' opening33 in;,the{;side;

wall of the casing. AI SWitCh-59302111101511 the" operation of theIhumldifier; The temperature? and humidity in the; casing; are-nindicatedfbyray suitable thermometer it and humldlstat GB' andi the, thermostatxfififprovldes an automatic control of the heating element 393' ''L'l'lelwindows The rotation" of the driving, motor 25'; foruturning the shaft and trays both as'to the direction, and extent ofI-Ioperation iscontrolled by means oftheI switchmechanism in- I dicated atrFig. 4 which in turn is controlled by the rotating disk for actuatingthe switch. The swltch comprises the pivotedkarm-or. cam lever 15 piyotedI- intermediate its length at 11 and having the contact extension 19 at its upper end to engage the cam faces or notchestI-I onthe disl; 83 and carrying at its lower end the two contact members 85 and-81 which are connected in suitable manner with the supply or line wires wand-9| respectively. Two pairs ofifixed 6023*:

tactsII93.Iand 95 for rotation in-one direction of the cam lever. The gearing between theIIpow'I- ermotor and the shaft carrying the egg trays is such thatgduring this closing of the motor.

I circult the shaft and trays will be rotated in a clockwise dlrection,II as heretofore explained;

vided: with a. series of;clrcular partltionstIII to.

" facilltatethe placlngpfthe eg s in the; trays I I through a distance of f.

Disk 83 will e removed atithe endIo f the first I only has 'aseries of notches I65, butextensions 4h IOL TheseI extensions, it. will be noted, actuate theiicontrollmg switch to close the rightvhand, murmurs-as andIah-lfi, causing] the motor to rotate the shaft and trays in the counterclock; wise directionand'to an extent preferably inthe neighborhood of 90. notches H35 cause rotation in the clockwise direction of approximately. 30. each, thus returning I theshaft and trays to their original or starting positiom g'lhus the shaft andIIegg trays will be rotated throughout the second week in. theIman: ner heretofore described as the third alternative in the foregoing description. I I

its showninFig; 1, the drivingImotor and its controls are located'Ijina closed compartment in the base of the apparatus, accessbeingafiorded I by the hinged doors I39. Ina second compartmenIt in the base are located thehumidifying apparatus in the lower part and the heater venti-I lating fan and motor in the upper part. The

remaining space beneaththe cylindrical casing 3|; also closed in with hinged doors; may be utilized for'the hatching, the eggsIbein transferred frorn the circular egg trays to suitable. hatching traysxf'or this purpose.

- "InIorder to showat a glance that the apparatus I is in operatingcondition with.thesourceiof'elece' provided on the outside of the basewhich will be I II I I 51. filledi withz glass'or other transparent ima- I terlal afford a' view of the interior of the I After this, the. three first week of incubation period, disk 83'will be driven by the control motor and the shaft willbe actuated clockwise each four hours, being turned through 60 of rotation. I During this period; the heating unit is in turn under the control of the thermostat and the humidifier is similarly operated and controlled by the humidistat. T 1 At the end of the week, the disk 83 isremoved from the control mechanism and disk H13 substituted, and thereafter the shaft is turned every four hours clockwise through 90 of rotating, being returned by a series of counterclockwise movements each hour of 30 each. Disk I03 may be continued in, operation, if desired, up to the eighteenth day, when the eggs will be transferred'from the circular trays to the hatching trays, freeing'the apparatus for another lot of eggs. It, will be noted that due to the inclined position of the actuating shaft, and the arrangement oi the egg trays thereon, the rotation of the shaft effects a turning or rotation of the eggs about their longitudinal axes, as distinguished from thetipping or tilting of the eggs about their short or transverse axes, as commonly practised inthe present types of incubators. I In this prior tilting method, the embryo is carried from a position directly above to a position directl below thelongitudinal axisc-f the egg, as distinguished from my method of partial rotation where the embryo is carried from above such axis tooneside thereof so that its return movement is definite and predetermined. Furthermore, my method of rotation enables me to control and limit theextent of displacement of the embryo from its top position. Furthermore, I am enabled to turn the eggs always in the same direction, thus insuring during the first week of incubation the maintaining'of the embryo in the best position for return to its normal location at the upper part of the egg.

While my improved apparatus is designed primarily to turn and manipulate the eggs in accordance'with my improved method, it is obvious that it may be operated according to any of the prior methods merely by substituting control disks of the proper type.

While I have described my method and appa- I ratus as used for the incubation of hens eggs, it is obvious that they are also adapted for the incubation of the eggs of other kinds and types of fowl by the substitution of the appropriate control disks and where necessary, by changes in the egg trays to accommodate other sizes of eggs.

In the foregoing specification and in the accompanying drawing, I have shown what is new considered to be a preferred form of apparatus for carrying out the present invention, but it is to be understood that the invention, in its broader aspects, is not limited to use with apparatus having the specific details of construction therein described and shown but may be carried out with other forms thereof. 7

,I-Iavingthus described the invention, what is claimed is:

c1. That step in1the process of incubation of eggs which consists in'imparting a series of periodic; rotational movements to the egg about a,

longitudinal axis which is inclined to the horizontaland in a clockwise direction viewing the egg from the large end the axis of the egg extending in'the same direction as the first mentioned axis, and the large end of the egg being elevated, the extent of each rotational movement being substantially less than a half revolution and such series, of rotational =movements being continued throughout approximately thefirst week of the incubation period.

2. That step in the process of incubation of eggs which consists in imparting a series of periodic rotational movements to the egg about aeggs which consists in imparting a series of peri odic rotational movements to the egg about a longitudinal axis which is inclined to the horizontal and in a clockwise direction viewing the egg from the large end the axis of the egg extending in the same direction as the first mentioned axis, and the large end of the eg being elevated, the extent of each rotational movement being substantially less than a half revolution and such series of rotational movements being continued throughout approximately the first week of the i-ncubatiomperiod, and thereafter imparting rotational movements to the egg periodically at some timesin one direction and othertimes in the other;

4. That step in the process of incubation of eggs'which consists in imparting a series of periodic rotational movements to the egg about a longitudinal axis which is inclined to the horizontal and in a "clockwise direction viewing the egg from the large end the axis of the egg extending in thesame'direction as the first mentioned axis, and the'large end of the egg being elevated, the extent of each rotational movement being substantially less'than a half revolution and such series of rotational movements being continued throughout approximately the first week of the incubation period, and thereafter periodically imparting rotational'movements to the egg alternately in opposite directions. 5. That step in the process of incubation of eggs which consists in imparting a series of periodic rotational movementsto the'egg about a longitudinal axis which is inclined to the horizontal and in a clockwise direction viewing the egg from I the large end the axis of the egg extending in the same direction as the first mentioned axis, and

I the large end of the egg b ing elevated, the extent 6. That step in the process of incubation of eggs which consists in imparting a series of periodic rotational movements to the egg about a 1ongitudinal axis which is inclined to the horizontal and in a. clockwise direction viewing the egg from the large end the axis of the egg extending in the same direction as the first mentioned axisiand the large end of the egg being elevated, the extent of each rotational movement being substantially less than a half revolution and such series of rotational movements being continued throughout approximately the first week of the incubation period, and thereafter imparting a second series of periodic rotational movements to theegg, each less than acomplete rotation, a-

rotational movement in one direction being followed by a plurality of spaced shorter rotational movements in the opposite direction to return the egg to its original position.

'7. That step in the process of incubation of eggs which consists in elevating the eggs so that their longitudinal axes are inclined at an angle to the horizontal with the larger end upward, and

while the eggs are so elevated imparting at the beginning of the incubation period a series of periodic rotational movements to the e gs about 0 their longitudinal axes and in a, clockwise direc- ,to the horizontal with the larger end upward, and

while the eggs are so elevated imparting a series i of periodic rotational movements to the eggs about their longitudinal axes and in a clockwise direction viewing the eggs from their large ends,

the extent of each rotational movement being substantially less than a half revolution and such series of rotational movements being continued throughout a period of approximately seven days from the beginning of the incubation period, and thereafter imparting rotational movements to the eggs periodically sometimes in one direction and other times in the other direction.

9. That step in the process of incubation of eggs which consists in elevating the eggs so that their longitudinal axes are at an angle to the horizontal with the larger end upward, and while,

the eggs are so elevated imparting aseries of periodic rotational movements to the eggs about their longitudinal axes and in a clockwise direction viewing the eggs from their large ends, the extent of each rotational movement being substantially less than a half revolution and such series of rotational movements being continued through a period of approximately seven days from the beginning of the incubation period, and thereafter periodically imparting rotational movements to the eggs alternately in opposite directions.

10. That step in the process of incubation of eggs which consists in elevating the eggs so that their longitudinal axes are at an angle to the horizontal with the larger end upward, and while the eggs are 50 elevated imparting a series of periodic rotational movements to the eggs about their longitudinal axes and in a clockwise clirection viewing the eggs from their large ends, the extent of each rotational movement being substantially less than a half revolution and such series of rotational movements being continued through a period of approximately seven days from the beginning of the incubation period, and thereafter imparting a second series of periodic rotational movements eachless than a complete rotation comprising a-movement in one direction followed by a. plurality of spaced shorter rotational movements in the opposite direction.

ZING YANG KUO. 

